1,721,166 research outputs found
Improving the schedulability of soft real-time open dynamic systems: The inheritor is actually a debtor
Full text linkThis paper presents the Clearing Fund Protocol, a three layered protocol designed to schedule soft real-time sets of precedence related tasks with shared resources. These sets are processed in an open dynamic environment. Open because new applications may enter the system at any time and dynamic because the schedulability is tested on-line as tasks request admission. Top-down, the three layers are the Clearing Fund, the Bandwidth Inheritance and two versions of the Constant Bandwidth Server algorithms. Bandwidth Inheritance applies a priority inheritance mechanism to the Constant Bandwidth Server. However, a serious drawback is its unfairness. In fact, a task executing in a server can potentially steal the bandwidth of another server without paying any penalty. The main idea of the Clearing Fund Algorithm is to keep track of processor-time debts contracted by lower priority tasks that block higher priority ones and are executed in the higher priority servers by having inherited the higher priority. The proposed algorithm reduces the undesirable effects of those priority inversions because the blocked task can finish its execution in its own server or in the server of the blocking task, whichever has the nearest deadline. If demanded, debts are paid back in that way. Inheritors are therefore debtors. Moreover, at certain instants in time, all existing debts may be waived and the servers are reset making a clear restart of the system. The Clearing Fund Protocol showed definite better performances when evaluated by simulations against Bandwidth Inheritance, the protocol it tries to improve.Fil: Santos, Rodrigo Martin. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; ArgentinaFil: Lipari, Giuseppe. Scuola Superiore Sant’Anna; ItaliaFil: Santos, Jorge. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentin
La politica estera della Turchia e la seconda guerra del Nagorno-Karabakh
No full textTra il 27 settembre e il 9 novembre 2020 lo status quo nel Caucaso è stato stravolto. Dopo oltre vent’anni dalla fine della prima guerra del Nagorno-Karabakh nel 1994, Armenia e Azerbaigian sono tornate allo scontro armato sul campo, e l’esercito di Baku ha conquistato la maggior parte dei territori contesi, sotto controllo armeno fino a quel momento. Il ribaltamento delle posizioni tra occupante e occupato ha radici nei percorsi opposti di sviluppo economico e di incremento del potenziale militare dei due Paesi, ma è stato reso possibile da un cambiamento nell’assetto regionale di più ampio respiro. Questo studio si concentra sul ruolo della Turchia di Erdoğan, analizzandone la politica di forte sostegno agli obiettivi strategici azeri, e la rilevanza nel “primo conflitto postmoderno”
Resource partitioning among real-time applications
No full textWhen executing different real-time applications on a single processor system, one problem is how to compose these applications and guarantee at the same time that their timing requirements are not violated. A possible way of composing applications is through the resource reservation approach. Each application is handled by a dedicated server that is assigned a fraction of the processor. Using this approach, the system can be seen as a two-level hierarchical scheduler. A considerable amount of work has been recently addressed to the analysis of this kind of hierarchical systems. However, a question is still unanswered: given a set of real-time tasks to be handled by a server, how to assign the server parameters so that the task set is feasible? In this paper, we answer to the previous question for the case of fixed priority local scheduler by presenting a methodology for computing the class of server parameters that make the task set feasible
A Resource Reservation Algorithm for Power-Aware Scheduling of Periodic and Aperiodic Real-Time Tasks
No full textACM SIGBED Review: Special Issue 3rd Workshop on Compositional Theory and Technology for Real-Time Embedded Systems (CRTS 2010)
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